Currently the assumed date/time type definitions in the Support IM follow the
ISO8601 standard very closely. Two problems with ISO 8601 however should be
1. partial date/times can only have missing seconds and minutes, but in real
systems, hours, days and months might be missing - this should not prevent
a partial value being captured. Secondly, HL7v2 and v3 implement this
deviation, meaning that some data exists following these pattersn.
2. the time 24:00:00 is ambiguous and probably should not be allowed,
particularly since in a date/time it implies the first second in the next
day (or the 0th second in the 1st hour of the next day, to be precise).